The present invention concerns interferometers and is particularly concerned, with Fourier transform spectrometers. Fourier transform spectroscopy is a well known technique for obtaining the spectra of weak extended sources. It offers throughput and multiplex advantages which can give rise to superior signal-to-noise performance when compared to other methods.
As a result there has been an increasing demand for Fourier transform spectrometers over a wide range of applications including industrial, medical, environmental and consumer applications.
Accordingly there has been a trend of simplifying and ruggidising spectrometer instrumentation to enable it to be used in an extended range of applications. There is however a trade-off between performance and cost associated which tends to limit the range of applications of emerging products.
The present invention is particularly concerned with providing an extremely simple and robust component for a spectrometer as well as improved Fourier Transform Spectrometers.
In one aspect the invention provides optical block in which light to be analysed is internally reflected and combined to produce an interference fringe pattern which can be measured to provide a spectral analysis of the light.